I believe the helmets aren’t actually made of glass. They must be some kind of semi-permeable membrane that allows some materials to pass through (carbon dioxide, cigar smoke and ash, sonic bugle-weapon mouthpieces, etc.) while keeping breathable air in and pressurized against the vacuum of space.

I’ve read this comic. It was a disappointingly literal rewrite of the Pacific Campaign, with Aliens standing in for the Japanese. Probably an old Howling Commandos script they had leftover, and just decided to rewrite to remove all the references to “Nips”, “Japs”, “Slants” and “Moonmen”… well… okay that last one would still fit, I guess.

Lame. And they made Baron Strucker the villain. See, he was an Earthian, so he ought to be on the Earthian side, but instead he was on the aliens’ side, so he was bad.
Because Baron Strucker is bad, you see.
Please, sir, hit me with the hammer of lazy writing some more.